After making his first cut of the season here at the Houston Open, the young Ulsterman decided he required another outing before the season’s first major begins in 12 days time. McIlroy had until 5pm Florida time to declare himself for the event in San Antonio and after a session with his coach, Michael Bannon, he took it right to the wire before making the extraordinary late call to play.

Bannon had earlier revealed that he believed McIlroy was “ring rusty” after watching him shoot a 70 to scrape into the weekend at one-under.

McIlroy had been scheduled to make a two-day trip to Haiti in his role as a Unicef ambassador on Monday and Tuesday, but he has postponed it.

"Unfortunately, I have had to postpone my planned trip to Haiti, with UNICEF, due to a change in my playing commitments. I am a strong supporter of UNICEF's work and I was privileged to be given the opportunity to visit Haiti, with UNICEF, nearly two years ago," he said.

"We are currently looking at dates to reschedule my trip and I look forward to visiting Haiti very soon."

Next week's tournament takes place on a tight, windy course which Phil Mickelson, among others, has said “is not conducive to preparing for the Masters”. McIlroy was also due to arrive at Augusta next Saturday but that plan has been shelved.

McIlroy has clearly arrived at the verdict held by many in the game - that he simply has not played enough this year since changing to Nike clubs.

Friday’s second round was only the ninth competitive 18 holes he has completed in 2013 and although he showed plenty of guts he remains a pale shadow of the player who took the golfing world by storm last season. McIlroy lost the world No 1 position to Tiger Woods on Monday and while the Valero event will give him another chance to regain top spot, McIlroy’s entry is all about the neccessity for game-time.

After walking off mid-round at Honda Classic last month, there has been a marked change in his attitude. Evidently he is willing to do whatever it takes to recover his form. If nothing else, McIlroy proved yesterday that he can still produce what he has to. He was flirting with the cut-line, aware that one more loose shot would see him heading back to his Florida home with the crisis bells ringing loud.

“I walked on to the seventh green [his 16th] and saw I was tied for 77th,” McIlroy said. “I knew I needed a birdie coming in, which I was able to do. I played those last few holes really well when I sort of needed to.”

It was his second shot on the par-five eighth which meant most. In his opening 73, McIlroy had located the water to the right of the green before taking a double-bogey seven. “That was a key moment for me,” he said. “I knew that if I did what I did on Thursday that would likely be it.”

From 262 yards he found the green and with two putts he was the right side of the number. McIlroy might even have birdied the ninth, but he had to be satisfied with a one-under total, nine behind the leader Steve Wheatcroft.

“It now gives me the weekend, where I have two rounds to get more confidence in what I’m doing and to trust my swing,” Mcilroy said. “It’s more of a mental thing than a mechanical thing at this point. But I’m hitting it well and feel that everything is nearly there.”

Even with San Antonio, McIroy faces a race to recover the poise and purpose to go with his rhythm. It will be a tough ask, but at least he is in there fighting. His two-under round included two penalty shots on a erractic driving day which saw him hit only five fairways. His par-save on the par-five eight was particularly valiant. Wet off the tee, McIlroy made an up and down from 30 yards.

It was encouraging to see him battling so hard, just as it was encouraging later to learn of his Texas entry. Inevitably the organisers were ecstatic. Larson Segerdahl, the tournament’s executive director, revealed that he had been in talks with McIlroy’s management for the past few weeks and that Greg Norman, whose company manages the Texas Open, had spoken to McIlroy. They believed their efforts had been in vain - until the phone rang at 4.30pm.

The perpetual drama that is ­McIlroy’s career overshadowed the second day of the Houston Open. Wheatcroft, a journeyman, who came through Monday qualifying, holds a one-shot lead over fellow American Jason Kokrak, while Brian Davis leads the British challenge three behind on seven-under after a 70. Lee Westwood is lurking on four-under after a level-par 72.